Abstract: From one aspect, the invention is a method of making a bending wave panel loudspeaker, comprising rigidly coupling a lever to a panel edge or marginal portion such that the lever extends at an angle to the plane of the panel, coupling a bending wave exciter to the lever whereby bending wave energy is coupled to the panel to produce an acoustic output when the exciter is fed with a signal and supporting the panel on a suspension positioned outboard of the lever. From another aspect the invention is a bending wave panel-form loudspeaker having a lever rigidly coupled to a marginal portion or edge of the panel, a vibration exciter coupled to the lever to apply bending wave energy to the panel to produce an acoustic output and a panel suspension positioned outboard of the lever. From a further aspect, the invention is a small electronic device, e.g.

Abstract: A loudspeaker assembly comprising a visual display screen, a resonant panel-form member positioned adjacent to the display screen, and a vibration exciter to cause the panel-form member to resonate as an acoustic resonator. At least a portion of the panel-form member is transparent, through which portion the display screen is visible.

Abstract: A loudspeaker comprising a resonant panel-form member adapted to produce an acoustic output and a vibration exciting system on the panel-form member and adapted to apply bending wave energy thereto, characterised in that the vibration exciting system is adapted to apply a bending couple to the panel-form member.

Abstract: A bending wave loudspeaker comprising a panel-form radiator and an electromechanical vibration exciter coupled to the radiator, wherein the bending stiffness of the radiator is in the range 0.001 to 1000 Nm, wherein the coupling between the exciter and the radiator is such that a component of the applied energy results in compression waves in the radiator and wherein the radiator has a break in mid-plane symmetry resulting in acoustic radiation. A method of making a bending wave loudspeaker comprising selecting a panel-form radiator and an electromechanical vibration exciter, coupling the exciter to the radiator to have a relationship between the electromechanical impedance of the vibration exciter and the mechanical impedance of the radiator useful to the operating bandwidth of the radiator, arranging the bending stiffness of the radiator to be in the range 0.

Abstract: A loudspeaker comprising a resonant panel-form member adapted to produce an acoustic output and a vibration exciting system on the panel-form member and adapted to apply bending wave energy thereto, characterized in that the vibration exciting system is adapted to apply a bending couple to the panel-form member.

Abstract: A loudspeaker assembly comprising a visual display screen, a resonant panel-form member positioned adjacent to the display screen, and a vibration exciter to cause the panel-form member to resonate as an acoustic resonator. At least a portion of the panel-form member is transparent, through which portion the display screen is visible.

Abstract: A loudspeaker drive unit comprising a visual display screen, a resonant panel-form member positioned adjacent to the display screen and at least a portion of which is transparent and through which the display screen is visible, and vibration exciting means to cause the panel-form member to resonate to act as an acoustic radiator.

Abstract: A loudspeaker comprises a panel member (11, 21, 31, 41, 61, 71, 81, 91) as resonant acoustic radiator relying on bending wave action and a driver (12, 22, 32, 42, 62, 72, 82, 92) coupled to the panel member to cause bending waves therein. The panel member has its mass and/or bending capability of the panel member locally altered or otherwise different, particularly locally of the driver as coupled to the panel member. Local holes (16, 26, 36, 46), affixed mass (66) or affixed damping material (76) are effective to reduce high frequency due to drumming effects at the driver coupling (17, 37, 47, 67, 77, 87).

Abstract: A loudspeaker comprising a resonant panel-form member adapted to produce an acoustic output and a vibration exciting system on the panel-form member and adapted to apply bending wave energy thereto, characterised in that the vibration exciting system is adapted to apply a bending couple to the panel-form member.

Abstract: A loudspeaker drive unit comprising a visual display screen, a resonant panel-form member positioned adjacent to the display screen and at least a portion of which is transparent and through which the display screen is visible, and vibration exciting means to cause the panel-form member to resonate to act as an acoustic radiator.

Abstract: An acoustic device, e.g. a loudspeaker, has a transducer (38) coupled via a highly perforate member (36) to an acoustically active area (39) that may be in the form of a skin over part of the highly perforate member. The highly perforate member (36) may be a mesh. Bending waves may be excited in the highly perforate member (36) by the transducer (38) and sound emitted from the acoustically active area (39).